International multicenter evaluation of autoantibodies to ribosomal P proteins.

Autoantibodies to the ribosomal phosphoproteins (Rib-P) are a serological feature of patients with systemic lupus erythematosus (SLE). The reported prevalence of anti-Rib-P antibodies in SLE ranges from 10 to 40%, being higher in Asian patients. The variation in the observed frequency may be related to a number of factors but is dependent in large part on the test system used to detect the autoantibodies. An association of anti-Rib-P with central nervous system involvement and neuropsychiatric manifestations of SLE has been controversial. In the present international multicenter study, we evaluated the clinical accuracy of a new sensitive Rib-P-specific enzyme-linked immunosorbent assay based on recombinant Rib-P polypeptides. The results showed that 21.3% of 947 SLE patients, but only 0.7% of 1,113 control patients, had a positive test result (P < 0.0001). The sensitivity, specificity, positive and negative predictive values, and diagnostic efficiency were determined to be 21.3%, 99.3%, 95.6%, 62.2%, and 65.3%, respectively. When evaluated in the context of participating centers, the prevalence of anti-Rib-P antibodies was found in descending frequency, as follows: China (35%) > Poland (34%) > Japan (28%) > United States (26%) > Germany (Freiburg; 23.3%) > Denmark (20.5%) > Germany (Berlin; 19%) > Mexico (15.7%) > Israel (11.7%) > Brazil (10%) > Canada (8%). The substantial data from this study indicate that the prevalence of anti-Rib-P antibodies may not be restricted to the genetic background of the patients or to the detection system but may depend on regional practice differences and patient selection. We confirm previously reported associations of antiribosomal antibodies with clinical symptoms and serological findings. Remarkably, we found a lower occurrence of serositis in Rib-P-positive lupus patients.

Prevalence of the rheumatic diseases in urban Vietnam: a WHO-ILAR COPCORD study.

OBJECTIVE: To determine the prevalence rates of musculoskeletal disorders in an urban Vietnamese population. METHODS: The Community Oriented Program for Control of Rheumatic Disease (COPCORD) Stage I study was carried out in 16 groups in the Trung Liet Commune, Dong Da District, Hanoi City, Vietnam. Phase 1: the WHO ILAR COPCORD Core Questionnaire was applied by primary health care workers to 2119 urban subjects aged 16 years and over. Phase 2: 276 positive responders who had musculoskeletal complaints were interviewed by nurses and examined one week later. Phase 3: 261 positive responders in phase II were examined by 3 rheumatologists and 38% of these subjects required radiographic and blood tests to classify rheumatic disease categories. RESULTS: The response rates were 94.4%, 86.2%, and 94.6% in phases 1, 2, and 3, respectively. The prevalence of musculoskeletal pain was 14.9%. The most common musculoskeletal complaints were knee pain 18.2%, low back pain 11.2%, and soft tissue disorder 15.4%. Functional disability was reported in 6.04% of the survey population. The prevalence of rheumatic diseases was OA 4.1%, rheumatoid arthritis 0.28%, osteoporosis 0.47%, connective tissue disease 0.09%, and gout 0.14%. CONCLUSION: The prevalence of musculoskeletal pain in 2119 adults in an urban population in Vietnam was 14.5%, and osteoarthritis was the most commonly found arthritis.